Recently, polyester resin has been used as a as a material for use in LEDs (light emitting diodes) devices. The polyester has been used in LED components requiring excellent energy efficiency and energy lifespan, such as reflectors, reflector cups, scramblers and LED housings. The polyester used in LED components is high heat resistance modified polyester resin reinforced by glass fiber and including benzene rings in the main chains of the polyester.
Till now, liquid crystal polymer (LCP) which exhibits high heat resistance has been used as reflectors of LED components. However, deterioration and unevenness are generated by using LCP for long period.
Due to solve the problem of LCP, modified polyester resin having high heat resistance is used instead of LCP. Modified polyester resin having high heat resistance should exhibit high heat resistance during the manufacture of a light emitting diode, excellent reflectance with an initial high whiteness index. At the same time, modified polyester resin used in LEDs should exhibit minimal deterioration of whiteness resulting from yellowing. Also, modified polyester resin used in LEDs should exhibit the ability to block the flow of electricity.
LEDs generally include a semiconductor emitting a light, a lead wire, a reflector as a housing, and a transparent sealing product sealing a semiconductor. Among these, the reflector can be made by various materials such as ceramic or heat resistant plastics. Productivity, however, of ceramics can be problematic, and heat resistant plastic can have decreased optical reflectance resulting from a change in color during the injection molding process.
The present invention relates to new modified polyester resin having high heat resistance that can substitute ceramic or heat resistant plastic used in reflectors of LEDs.